产胶植物Sec23/Sec24蛋白调控橡胶粒子发育的机制研究

橡胶粒子是产胶植物特有的合成和储存天然橡胶的细胞器，其与脂滴同样具有罕见的磷脂单分子层膜结构（半个单位膜）。橡胶粒子膜表面丰度最高的蛋白是小橡胶粒子膜蛋白（SRPP），拟南芥中异位表达SRPP定位于脂滴上，进化分析发现SRPP在产胶植物和产油植物中均发生了基因家族扩张现象，由此推测橡胶粒子与脂滴具密切关系。我们在橡胶树中进行橡胶粒子和脂滴的比较蛋白组学研究，鉴定到橡胶粒子特有的Sec23/Sec24家族蛋白，主要调控囊泡发育，参与内质网-高尔基体物质运输。我们因此提出该蛋白家族对橡胶粒子发育具有重要调控作用。本项目拟开展Sec23/Sec24家族蛋白的进化、基因及蛋白表达谱分析，亚细胞定位分析，蛋白互作及转基因功能验证，初步阐明Sec23/Sec24家族蛋白对橡胶粒子发育的调控机制。研究结果有助于加深对橡胶粒子进化起源的理解，并为分子遗传育种提高橡胶产量提供理论支持。

Rubber particle (RP) is an organelle unique to the rubber-producing plants where biosynthesize and storage of natural rubber take place. It has a rare phospholipid monolayer membrane structure (half unit membrane), as well as lipid droplet (LD). The most abundant protein on the surface of the rubber particle membrane is small rubber particle protein (SRPP). Ectopic expression of SRPP in Arabidopsis resulted in lipid droplets localization. Evolutionary analysis identified gene family expansion in both rubber-producing and oil-producing plants. Thus, we illustrated that RPs have close relationship with LDs. Comparative proteomics studies between rubber particles and lipid droplets have been performed in rubber tree, identifying Sec23 / Sec24 family proteins which are unique to rubber particles. This protein family was reported to mainly regulate vesicle development, and to involve in ER-Golgi transport. We then proposed that this protein family plays crucial roles in regulating rubber particle development. This project intends to carry out the evolutionary analysis, gene and protein expression profiling analysis, subcellular localization analysis, protein-protein interaction and transgene analyses of Sec23 / Sec24 family proteins, basically illustrating the mechanism of Sec23 / Sec24 family proteins in regulating rubber particle development. The results will be helpful to better understanding of the evolutionary origin of rubber particles and will provide theoretical support for molecular genetic breeding for rubber yield improvement.